Search for Extremely-High-Energy Neutrinos and First Constraints on the Ultrahigh-Energy Cosmic-Ray Proton Fraction with IceCube
Physical Review Letters American Physical Society (APS) 135:3 (2025) 031001
Authors:
R Abbasi, M Ackermann, J Adams, SK Agarwalla, JA Aguilar, M Ahlers, JM Alameddine, NM Amin, K Andeen, C Argüelles, Y Ashida, S Athanasiadou, SN Axani, R Babu, X Bai, A Balagopal V., M Baricevic, SW Barwick, S Bash, V Basu, R Bay, JJ Beatty, J Becker Tjus, J Beise, C Bellenghi, S BenZvi, D Berley, E Bernardini, DZ Besson, E Blaufuss, L Bloom, S Blot, F Bontempo, JY Book Motzkin, C Boscolo Meneguolo, S Böser, O Botner, J Böttcher, J Braun, B Brinson, Z Brisson-Tsavoussis, J Brostean-Kaiser, L Brusa, RT Burley, D Butterfield, MA Campana, I Caracas, K Carloni, J Carpio, S Chattopadhyay, N Chau, Z Chen, D Chirkin, S Choi, BA Clark, A Coleman, P Coleman, GH Collin, A Connolly, JM Conrad, R Corley, DF Cowen, C De Clercq, JJ DeLaunay, D Delgado, S Deng, A Desai, P Desiati, KD de Vries, G de Wasseige, T DeYoung, A Diaz, JC Díaz-Vélez, P Dierichs, M Dittmer, A Domi, L Draper, H Dujmovic, D Durnford, K Dutta, MA DuVernois, T Ehrhardt, L Eidenschink, A Eimer, P Eller, E Ellinger, S El Mentawi, D Elsässer, R Engel, H Erpenbeck, W Esmail, J Evans, PA Evenson, KL Fan, K Fang, K Farrag, AR Fazely, A Fedynitch, N Feigl, S Fiedlschuster, C Finley, L Fischer, D Fox, A Franckowiak, S Fukami, P Fürst, J Gallagher, E Ganster, A Garcia, M Garcia, G Garg, E Genton, L Gerhardt, A Ghadimi, C Girard-Carillo, C Glaser, T Glüsenkamp, JG Gonzalez, S Goswami, A Granados, D Grant, SJ Gray, S Griffin, S Griswold, KM Groth, D Guevel, C Günther, P Gutjahr, C Ha, C Haack, A Hallgren, L Halve, F Halzen, L Hamacher, H Hamdaoui, M Ha Minh, M Handt, K Hanson, J Hardin, AA Harnisch, P Hatch, A Haungs, J Häußler, K Helbing, J Hellrung, J Hermannsgabner, L Heuermann, N Heyer, S Hickford, A Hidvegi, C Hill, GC Hill, R Hmaid, KD Hoffman, S Hori, K Hoshina, M Hostert, W Hou, T Huber, K Hultqvist, M Hünnefeld, R Hussain, K Hymon, A Ishihara, W Iwakiri, M Jacquart, S Jain, O Janik, M Jansson, M Jeong, M Jin, BJP Jones, N Kamp, D Kang, W Kang, X Kang, A Kappes, D Kappesser, L Kardum, T Karg, M Karl, A Karle, A Katil, U Katz, M Kauer, JL Kelley, M Khanal, A Khatee Zathul, A Kheirandish, J Kiryluk, SR Klein, Y Kobayashi, A Kochocki, R Koirala, H Kolanoski, T Kontrimas, L Köpke, C Kopper, DJ Koskinen, P Koundal, M Kowalski, T Kozynets, N Krieger, J Krishnamoorthi, T Krishnan, K Kruiswijk, E Krupczak, A Kumar, E Kun, N Kurahashi, N Lad, C Lagunas Gualda, M Lamoureux, MJ Larson, F Lauber, JP Lazar, K Leonard DeHolton, A Leszczyńska, J Liao, M Lincetto, YT Liu, M Liubarska, C Love, L Lu, F Lucarelli, W Luszczak, Y Lyu, J Madsen, E Magnus, KBM Mahn, Y Makino, E Manao, S Mancina, A Mand, W Marie Sainte, IC Mariş, S Marka, Z Marka, M Marsee, I Martinez-Soler, R Maruyama, F Mayhew, F McNally, JV Mead, K Meagher, S Mechbal, A Medina, M Meier, Y Merckx, L Merten, J Mitchell, T Montaruli, RW Moore, Y Morii, R Morse, M Moulai, T Mukherjee, R Naab, M Nakos, U Naumann, J Necker, A Negi, L Neste, M Neumann, H Niederhausen, MU Nisa, K Noda, A Noell, A Novikov, A Obertacke Pollmann, V O’Dell, A Olivas, R Orsoe, J Osborn, E O’Sullivan, V Palusova, H Pandya, N Park, GK Parker, V Parrish, EN Paudel, L Paul, C Pérez de los Heros, T Pernice, J Peterson, A Pizzuto, M Plum, A Pontén, Y Popovych, M Prado Rodriguez, B Pries, R Procter-Murphy, GT Przybylski, L Pyras, C Raab, J Rack-Helleis, N Rad, M Ravn, K Rawlins, Z Rechav, A Rehman, E Resconi, S Reusch, W Rhode, B Riedel, A Rifaie, EJ Roberts, S Robertson, S Rodan, M Rongen, A Rosted, C Rott, T Ruhe, L Ruohan, D Ryckbosch, I Safa, J Saffer, D Salazar-Gallegos, P Sampathkumar, A Sandrock, M Santander, S Sarkar, S Sarkar, J Savelberg, P Savina, P Schaile, M Schaufel, H Schieler, S Schindler, L Schlickmann, B Schlüter, F Schlüter, N Schmeisser, T Schmidt, J Schneider, FG Schröder, L Schumacher, S Schwirn, S Sclafani, D Seckel, L Seen, M Seikh, M Seo, S Seunarine, P Sevle Myhr, R Shah, S Shefali, N Shimizu, M Silva, B Skrzypek, B Smithers, R Snihur, J Soedingrekso, A Søgaard, D Soldin, P Soldin, G Sommani, C Spannfellner, GM Spiczak, C Spiering, J Stachurska, M Stamatikos, T Stanev, T Stezelberger, T Stürwald, T Stuttard, GW Sullivan, I Taboada, S Ter-Antonyan, A Terliuk, M Thiesmeyer, WG Thompson, J Thwaites, S Tilav, K Tollefson, C Tönnis, S Toscano, D Tosi, A Trettin, MA Unland Elorrieta, AK Upadhyay, K Upshaw, A Vaidyanathan, N Valtonen-Mattila, J Vandenbroucke, N van Eijndhoven, D Vannerom, J van Santen, J Vara, F Varsi, J Veitch-Michaelis, M Venugopal, M Vereecken, S Vergara Carrasco, S Verpoest, D Veske, A Vijai, C Walck, A Wang, C Weaver, P Weigel, A Weindl, J Weldert, AY Wen, C Wendt, J Werthebach, M Weyrauch, N Whitehorn, CH Wiebusch, DR Williams, L Witthaus, M Wolf, G Wrede, XW Xu, JP Yanez, E Yildizci, S Yoshida, R Young, F Yu, S Yu, T Yuan, A Zegarelli, S Zhang, Z Zhang, P Zhelnin, P Zilberman, M Zimmerman
Abstract:
We present a search for the diffuse extremely-high-energy neutrino flux using 12.6 years of IceCube data. The nonobservation of neutrinos with energies well above 10 PeV constrains the all-flavor neutrino flux at 1018 eV to a level of E2Φνe+νμ+ντ≃10−8 GeV cm-2 s-1 sr-1, the most stringent limit to date. Using these data, we constrain the proton fraction of ultrahigh-energy cosmic rays (UHECRs) above ≃30 EeV to be ≲70% (at 90% CL) if the cosmological evolution of the sources is comparable to or stronger than the star formation rate. This is the first result to disfavor the “proton-only” hypothesis for UHECR in this evolution regime using neutrino data. This result complements direct air-shower measurements by being insensitive to uncertainties associated with hadronic interaction models. We also evaluate the tension between IceCube’s nonobservation and the ∼200 PeV KM3NeT neutrino candidate (KM3-230213A), finding it to be ∼2.9σ based on a joint-livetime fit between neutrino datasets.
